The present invention relates to circuits and systems incorporating solid-state devices referred to herein as xe2x80x9ctranspinnorsxe2x80x9d and described in U.S. Pat. Nos. 5,929,636 and 6,031,273, the entire disclosures of which are incorporated herein by reference for all purposes. More specifically, the present application describes a transpinnor-based sample-and-hold circuit and various applications thereof.
The vast majority of electronic circuits and systems manufactured and sold today are based on semiconductor technology developed over the last half century. Semiconductor processing techniques and techniques for manufacturing integrated circuits have become increasingly sophisticated resulting in ever smaller device size while increasing yield and reliability. However, the precision of such techniques appears to be approaching its limit, making it unlikely that systems manufactured according to such technique will be able to continue their historical adherence to Moore""s Law which postulates a monotonic increase in available data processing power over time.
In addition, as the techniques for manufacturing semiconductor integrated circuits have increased in sophistication, so have they correspondingly increased in cost. For example, current state-of-the-art integrated circuits require a large number of processing steps to integrate semiconductor circuitry, metal layers, and embedded circuits, an issue which is exacerbated by the varied nature of the materials being integrated. And the demand for higher levels of complexity and integration continue to grow. The technical difficulties facing the semiconductor industry are well summarized by P. Packan in the Sept. 24th, 1999, issue of Science magazine beginning at page 33, incorporated herein by reference in its entirety for all purposes.
Finally, there are some applications for which conventional semiconductor integrated circuit technology is simply not well suited. An example of such an application is spacecraft systems in which resistance to external radiation is extremely important. Electronic systems aboard spacecraft typically require elaborate shielding and safeguards to prevent loss of information and/or system failure due to exposure to any of the wide variety of forms of radiation commonly found outside earth""s atmosphere. Not only are these measures costly in terms of dollars and weight, they are not always completely effective, an obvious drawback given the dangers of space travel.
In view of the foregoing, it is desirable to provide electronic systems which facilitate higher levels of integration, reduce manufacturing complexity, and provide a greater level of reliability in a wider variety of operating environments.
According to the present invention, electronic circuits and systems based on an all-metal solid-state device referred to herein as a xe2x80x9ctranspinnorxe2x80x9d address the issues discussed above. More specifically, an embodiment of the present invention provides a sample-and-hold circuit based on the transpinnor which may be used in any larger circuit in which a conventional sample-and-hold circuit might be employed, e.g., an analog-to-digital converter.
Thus, the invention provides a sample-and-hold circuit which includes a network of thin-film elements in a bridge configuration. Each of the thin-film elements exhibits giant magnetoresistance and has a first magnetic film associated therewith which is operable to magnetically bias the associated thin-film element. The circuit also includes a plurality of conductors inductively coupled to each of the thin-film elements for applying magnetic fields thereto. The circuit is operable using the plurality of conductors to sample and store a value corresponding to an input signal.
According to another embodiment, the present invention provides a sample-and-hold circuit comprising a network of thin-film elements in a bridge configuration. Each of the thin-film elements exhibits giant magnetoresistance. A plurality of conductors are inductively coupled to each of the thin-film elements for applying magnetic fields thereto. The circuit is operable using the plurality of conductors to generate a substantially constant output current representative of an input signal using a remanent magnetization associated with at least one of the thin-film elements.
According to yet another embodiment, the present invention provides a sample-and-hold circuit comprising a network of thin-film elements in a bridge configuration. Each of the thin-film elements exhibit giant magnetoresistance. The circuit also includes a signal conductor operable to transmit an input signal, and a sample conductor operable to transmit a strobe signal. The signal and sample conductors are inductively coupled to selected ones of the thin-film elements. The circuit is operable to sample and store a value corresponding to the input signal in response to the strobe signal.
Various types of analog-to-digital converters employing the sample-and-hold circuits of the present invention are also provided. Electronic systems incorporating the sample-and-hold circuits and analog-to-digital converters are also within the scope of the invention.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.